A central quantity in quantum many-body physics is the single-particle Green's function, which describes the propagation of particles (or holes) in an interacting many-body system [1]}. For systems of interacting electrons without any explicit time dependence, the imaginary part of the frequency-dependent Green's function is related to the spectral function, \(A(\omega )\) , which can be measured, e.g., by techniques such as (angle-resolved) photoemission spectroscopy [2]}. However, numerical methods that work at finite temperature typically calculate the Green's function in imaginary time, \(G(\tau )\) , where \(\tau \in [0, \beta )\)  and \(\beta = 1/(k_\mathrm {B} T)\)  is the inverse temperature. In this case, an analytic continuation to real frequencies is required to obtain the physically relevant spectral function.
